Printing



Patented Apr. 1l, 1939' PATENT oFFIcE PRINTING Oswald R. Schultz, New York, N. Y., assigner to Cell-Type Plate Oo., Inc., Union City, N. J., a corporation of New York Application Augusty 28, 1933, Serial No. 687,025

7 Claims.

This invention relates to printing and more particularly to method of applying printing and decoration directly to metal, glass, asbestos, hard rubber, linoleum, libre, wood, and to other hard plates and surfaces.

It has heretofore been the practice in metal printing to first make a printing plate by the litho-offset process. A special type of ink is then used which is more in the nature of heavy oily m pigmentgwhich dries very slowly. The ink is applied to the offset plate and the ink then transferred from the offset plate to an offset rubber blanket or roller, The` offset roller with the ink thereon is then appliedto the metal sheet or other surface and the printing ink thus deposited thereon.

The process as above practiced has many serious objections. In the first place it is tedious,

time consuming and diicult to prepare litho-offset plates for use. Difficulties are further encountered in transferring the printing inks. to the transfer roller. Operating conditions must be carefully gauged. 'Ihe offset blanket or roller as well -as the metallic printing plate must be kept clean at all times. And even when the greatest care has been exercised, the offset roller becomes gummed with ink or ink becomes spattered thereon so that the printing Work becomes ruined. `Special inks of an oily nature must also be used which are expensive and require special treatment for drying. Drying ovens are generally required which are expensive to operate and which require considerable time to dry the inks thereon.

My process herein contemplates the applicay tion of printing to metal and other hard surfaces by means of a printing plate formed from cellulosic material.l The printing plate is preferably cast from a copy relief while the cellulosic 40 material is in a semi-plasticcondition. The `printing plate dries within a few minutes and is then removed from the copy relief and is ready for use.

In order that a clearer understanding of my invention may be had, attention is hereby directed to the accompanying drawing, forming a part of this application and illustrating certain possible embodiments of my invention.

Referring to the drawing,

Fig. 1 is a vertical cross sectional View through a continuous rotogravure printing cylinder hav,- ing a resilient rubber blanket anda cellulosic printing plate appliedv thereto and about to be moved into contact with the surface to be printed;

Fig. 2 is a fragmentary cross sectional view of the printing cylinder shown in Fig. 1 as it appears during the printing operation; and

Fig. 3 is a vertical cross sectional view through a printing cylinder of a sheet-fed type having the rubber blanket and the cellulosic printing plate-applied thereto.

Similar reference characters refer to similar parts throughout the several views of the drawing.

The printing cylinder I0, as shown in the drawing, may be of cast metal or other strong solid material. A blanket ll of resilient material surrounds the cylinder I0. The blanket Il may be formed of relatively soft resilient rubber or other similar resilient material which possesses a slight give.

The printing plate is preferably formed from cellulosic material which is cast while in a plastlc state from a suitable copy relief. The copy relief may be formed bythe photographic proc-4 ess in common use. This process comprises photographing the picture or representation by exposing the photographic plate, developing the same and then exposing a sensitized gelatine plate through the developed printing plate. After exposure the sensitized gelatine surface is swollen in water so as to bring out the picture in relief.

In making a rotogravure roll having a continuous surface, such as shown in Figs. 1 and 2, a backing..plate |20., preferably of cellulosic ma- -terial, is first applied to the rubber blanket Il.

The backing plate |2a may bemoulded to the cylinder in a suitable manner so as to provide a smooth and even surface. The cellulosic printing surface may be cast on to the backing |2a by placing the cellulosic printing material, while in a viscous plastic state, between the backing I2a,

and the copy relief. The character of the viscous plastic mass from which the printing plate is cast is more particularly described in my copending application, Serial No. 518,649, filed February 27, 1931. By rotating the cylinder, the plastic printing material may be rolled or squeegeed around the cylinder into contact with the copy relief and may be applied in the manner described in my copending application, Serial No. 631,261, led October 5, 1932. When the cellulosic material is hardened sufficiently, the copy relief is removed and the cylinder is ready for use in printing. If a sheet fed roller, such as shown in Fig. 3, is used, the cellulosic printing plate I2, having the printing surface I3 moulded thereon, may be applied directly to the rubber blanket Il and held in place by suitable clamps and bolts I8 in the manner shown in my copending application, Serial No. 519,713, led March 3, 1931.

The printing plate may be coated directly with the ink which becomes deposited` in the recesses of the printing surface I3. The surface I5 to be prin-ted is placed upon a suitable table I4 and the printing cylinder, coated with ink, is moved thereover. The ink I6 is deposited on the surface to be printed directly. Ordinary intaglio inks which are quick drying may be used. A transfer roller which is commonly used in printing on metallic surfaces is unnecessary where a cellulosic printing plate is used.

I have discovered, that the cellulose printing plate possesses characteristics which the metallic or copper printing plate does not possess. For instance, it is well known that it is impossible to print directly on to a metal surface from a metallic printing plate because the surface of the copper printing plate becomes damaged and injured when pressed into contact with the metal or other hard surfaces and areas. Furthermore, the inks would not transfer satisfactorily. I have discovered that by the use of a cellulosic printing plate as above described that I can print directly from the cylinder on to the metal surface or metal plate. No offset roller of any kind is required.

The explanation for these unusual results obtained cannot be accurately determined, but it is believed that it is due apparently to the inherent resilient characteristics of the cellulose plate.

It is not absolutely necessary to use a resilient blanket under the cellulosic printing plate, satisfactory results having been obtained Without its use. A resilient blanket under the plate, however, does give the cellulosic plate additional resiliency, which is advantageous in producing subjects of a delicate nature.

Heavy oily inks, such as now commonly used in metal printing, are not necessary when my cellulosic printing plate is used. intaglio inks commonly used for paper printing may be used for printing on metal or similar hard surfaces. The particular advantage of this is that intaglio inks dry almost immediately upon application and no drying ovens or other apparatus need be used for drying the inks on to the metal surface. Furthermore, it has been discovered that by means of my process, printing may be done directly on to the metal surface without first applying a ground or paint coating to the metal sheet.

The process above disclosed is especially advantageous in reproducing wood graining on wood 0r other surfaces The wood grain to be reproduced is photographed, a copy relief made, a cellulosic printing plate cast from the copy relief, and the printing inks applied by the printing cylinder directly on to the metallic surface. The process may be used to reproduce other representations such as stone, landscape scenes, pictures, photographs, reading matter, and other representations upon libre, stone, wood and other hard surfaces. The process can be carried out by unskilled labor and printing of the finest quality produced at a great saving in both time and the number of operations heretofore considered necessary.

While certain novel features of the invention have been disclosed and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

Wha-t is claimed is:

1. The process of decorating metallic and stone surfaces which includes, providing a printing plate composed of cellulosic materal, applying quick drying intaglio ink to the printing surface thereof, and transferring the ink deposited on said plate directly on to the surface to be decorated.

2. The process of decorating metallic surfaces which includes, providing a printing plate having a photographically toned printing surface of cellulosic material, applying quick drying ink to the printing surface thereof, and transferring the ink deposited on said plate directly on to the metallic surface to be decorated.

3. The process of decorating metallic surfaces which includes, providing a printing plate composed of cellulosic material having a photographically -toned printing surface, mounting said plate on a resilient blanket, applying ink to the printing surface thereof, and transferring the ink deposited on said plate directly on to the metallic surface to be decorated.

4. The process of decorating metallic surfaces which includes, providing a vprinting plate having a photographically toned printing surface of cellulosic material, mounting said plate on a resilient blanket, applying quick drying ink to the printing surface thereof, and transferring the ink deposited on said plate on to the metallic surface to be decorated.

5. The process of decorating metallic surfaces which includes, providing a printing plate having a photographically toned printing surface of cellulosic material, mounting said plate on a resilient blanket, applying quick drying ink to the surface thereof, transferring the ink deposited on said plate on to the metallic surface to be decorated, and covering said printed surface with a protective covering.

6. The process of reproducing designs on a solid surface such as stone, metal and hard earthy surfaces and the like which includes, providinga printing plate of cellulosic material having a photographically toned printing surface, applying quick drying intaglio ink to the printing surface thereof, and transferring the ink deposited on said plate on to the surface to be decorated.

7. The process of reproducing designs on a solid surface such as stone, metal and similar hard surfaces which includes, providing a printing plate having a photographically toned printing surface of resilient cellulosic material, mounting said plate on a resilient blanket, applying ink to the printing surface thereof, and transferring the ink deposited on said plate directly on to the surface to be decorated.

OSWAL'D R. SCHULTZ. 

